Light-sensitive element containing methine dyes



United States Patent 3,476,558 LIGHT-SENSITIVE ELEMENT CONTAINING METHINE DYES Henri Depoorter and Marcel Jan Libeer, Mortsel-Antwerp, Belgium, assignors to Gevaert-Agfa N.V., Mortsel, Belgium, a Belgian company No Drawing. Filed Nov. 24, 1965, Ser. No. 509,609 Claims priority, application Great Britain, Nov. 27, 1964, 48,269/ 64 Int. Cl. G03c 1/12, 1/22; C09b 23/10 U.S. Cl. 96-1.7 9 Claims ABSTRACT OF THE DISCLOSURE Light-sensitive photographic elements are described which include a merocyanine dye which contains a benzimidazothiazinone nucleus. These elements have extended spectral sensitivity.

each of R and R represents hydrogen or halogen e.g.

chlorine.

According to the present invention, new merocyanine dyes are provided, which correspond to the following general Formula II:

S O n N- orr=0H).. 1c'=oH-or1=o 1LT it, C K,

wherein R and R have the same significance as described above,

R represents an alkyl radical,

n is 1 or 2, and

Z represents the atoms necessary to complete a heterocyclic nitrogen nucleus containing 5 to 6 atoms in the heterocyclic ring such as those of the thiazole series (e.g. thiazole, 4-methy1thiazole, 4-phenylthiazo1e, S-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl) -thiazole) those of the benzothiazole series (e.g. benzothiazole, 4-chlorobenzothiazole,

3,476,558 Patented Nov. 4, 1969 S-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4 methylbenzothiazole, 5 methylbenzothiazole, 6-methylbenzothiazole, S-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiaz0le, 5-phenylbenzothiazole, 4-methoxybenzothiazole, S-methoxybenzothlazole, G-methoxybenzothiazole, S-iodobenzothiazole, -iodobenzothiazole, 4-ethoxybenzothiazole, S-ethoxybenzothiazole, 4,5,6,7-tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, 5,6-dimethylbenzothiazole), those of the naphthothiazole series (e.g. naphtho[2,1-d]thiazole, naphtho[1,2-d]thiazole, S-methoxynaphtho 1,2-d] thiazole, 5-ethoxynaphtho[1,2-d]thiazole, S-methoxynaphtho[2,1-d]thiazole, 7-methoxynaphtho[2,1-d]thiazo1e), those of the thionaphtheno[7,6-d] thiazole series (e.g. 7-methoxythionaphtheno[7,6-d]thiazole), those of the oXazole series (e.g. 4-rnethyloxazo1e, 5-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, S-phenyloxazole), those of the benzoxazole series (e.g. benzoxazole, 5-chlorobenzoxazole, 5 methylbenzoxazole, 5 phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6- dimethylbenzoxazole, S-methoxybenzoxazole, 6-methoxybenzoxazole, S-hydroxybenzoxazole, fi-hydroxybenzoxazole), those of the naphthoxazole series (e.g. naphtho [2,1-d1oxazole, naphtho[1,2-d]oxazole), those of the selenazole series (e.g. 4-methylselenazole, 4-phenylselenazole), those of the benzoselenazole series (e.g. benzoselenazole, S-chlorobenzoselenazole, S-methoxybenzoselenazole, S-hydroxybenzoselenazole, 4,5,6,7-tetrahydrobenzoselenazole), those of the naphthoselenazole series (e.g. naphth0[2,1 d]selenazole, naphtho[1,2 d]selenazole), those of the thiazoline series (e.g. thiazoline, 4-methylthiazoline, 4-hydroxymethyl-4-rnethylthiazoline, 4,4-bishydroxymethylthiazoline, 4-acetoxymethyl-4-methylthiazoline, 4,4-bis-acetoxymethylthiazoline), those of the oxazoline series (e.g. oxazoline, 4-hydroxymethyl-4- methyloxazoline, 4,4-bis-hydroxymethyloxazoline, 4-acetoxymethy1-4-methyloxazoline, 4,4-bis-acetoxymethyloxazoline), those of the selenazoline series (e.g. selenazoline), those of the Z-quinoline series (e.g. the quinoline, 3-methylquinoline, S-methylquinoline, 7methylquinoline, 8-methylquinoline, 6-chloroquinoline, 8-chloroquinoline, 6-rnethoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, S-hydroxyquinoline etc.), those of the 4-quinoline series (e.g. quinoline, 6-methoxyquinoline, 7-methylquinoline, S-methylquinoline), those of the l-isoquinoline series (e.g. isoquinoline, 3,4-dihydroisoquinoline), those of the 3-isoquinoline series (e.g. isoquinoline), those of the 3,3- dialkylindolenine series (e.g. 3,3-dimethylindolenine, 3,3,5- trimethylindolenine, 3,3,7-trimethylindo1enine), those of the pyridine series (e.g. pyridine, 5 -methy1pyridine), those of the benzimidazole series (e.g. l-ethylbenzimidazole, 1 phenylbenzimidazole, 1 ethyl 5,6 dichlorobenzimidazole, 1 hydroxyethyl 5,6 dichlorobenzimidazole, 1-ethy1-S-chlorobenzimidazole, 1-ethyl-5,6-dibromobenzimidazole, 1-ethyl-5-chloro-6-bromobenzimidazole, l-ethyI-S-phenylbenzimidazole, 1-ethyl-5-fluorobenzimidazole, 1-ethyl-5,G-difiuorobenzimidazole, 1-ethy1- 5 cyanobenzimidazole, l-(fl-acetoxyethyl) 5 cyanobenzirnidazole, 1-ethyl-5-chloro-fi-cyanobenzimidazole, l-ethyl-S-fluoro-6- cyanobenzimidazole, l-ethy]-5-acetylbenzirnidazole, l-ethyl-5-chloro-6-fluorobenzirnidazo1e, l-ethyl-S-carboxybenzimidazole, l-ethyl 7 carboxybenzimidazole, 1-ethyl-5- carbethoxybenzimidazole, 1-ethyl-7-carbethoxybenzimidazole, 1-5-su1phamylbenzimidazole, or l-ethyl-S-N-ethylsulpharnylbenzimid azole) The merocyanine dyes according to the general Formula II can be prepared by condensing a benzimidazothiazinone compound of the following general Formula III:

(III) R1 N 1012 N\ /CH: R

wherein R and R have the same significance as described above, with a heterocyclic quaternary ammonium salt according to the following general Formula IV:

wherein:

R Z and n have the same significance as described above,

D represents a ,B-acetanilidovinyl group or a fi-p-toluene sulphonanilidovinyl groups, and

X" represents an acid radical.

The condensations are advantageously carried out in the presence of a basic condensing agent, for example a trialkylamine such as triethylamine, a dialkylaniline, or a heterocyclic tertiary amine such as pyridine or N-alkylpiperidine. The condensations of this type can also be carried out by allowing the intermediates to react in the presence of an inert solvent such as methanol, ethanol, whilst heating if needed.

The following illustrates the preparation of compounds according to the general Formula III.

PREPARATION 1 4-oxo-3,4-dihydro-1H-l ,4-thiazino [4,3-a]benzimidazole is prepared as described by A. L. Misra, J. Org. Chem. 23 (1958) 897.

PREPARATION 2 (a) (5,6-dichloro-2-benzimidazolyl)-methane thiol A solution of 13.6 g. of 4,5-dichloro-o-pheuylenediamine and 9.4 g. of 80% thioglycolic acid in 80 ml. of 4 N hydrochloric acid is refluxed for 1 hour. The precipitated mercapto compound is purified by dissolution in sodium hydroxide and acidification with acetic acid. Yield: 12.7 g. Melting point: about 250 C. (with decomposition).

(b) 5,6-dichloro-2-benzimidazolyl) -methylthioacetic acid 12.7 g. of (5,6-dichloro-2-benzimidazolyl)-methane thiol and 5.4 g. of chloroacetic acid are dissolved in 65 ml.

4 of 2 N sodium hydroxide and boiled for 1 hour. Then, ml. of water are added and the mixture is boiled and filtered. The filtrate is acidified with acetic acid and the precipitate formed is washed with water and recrystallised from ethanol. Yield: 10.3 g. Melting point: 236 C.

(c) 7,8-dichloro-4-oxo-3,4-dihydro-lH-l,4-thiazino [4,3-a]benzimidazole 10.3 g. of (5,6-dichloro-2-benzimidazolyl)-methylthioacetic acid are dissolved in 30 ml. of pyridine, whereupon 5 ml. of acetic anhydride are added. The mixture is boiled for 3 min. and then cooled. The formed precipitate is sucked ofi and washed with ether. Yield: 7.3 g. Melting point: 213 C.

The following examples illustrate the preparation of merocyanine dyes according to the present invention.

EXAMPLE 1 3- 2-3-ethyl-2-thiazolidinylidene) -ethylidene] -4-oxo- 3 ,4-dihydro-lH-1,4-thiazino[4,3-a1benzimidazole EXAMPLE 2 3-[2-(3-ethyl 2 thiazolidinylidene)-ethylidene]-4- oxo-7,8-dichloro 3,4 dihydro-lH-l,4-thiazino[4,3-a] benzimidazole This product is prepared in the same way as that of Example 1, with the proviso, however, that the used amount of 4-oxo 3,4 dihydro-1H-1,4-thiazino[4,3-a] benzimidazole is replaced by 2.73 g. of 7,8-dichloro-4- oxo-3,4-dihydro 1H 1,4 thiazino[4,3-a]benzimidazole. Melting point: 240 C. )t =450 nm. E:5.5O 104.

1 kg. of a gelatino-silver chlorobromide emulsion is sensitised with 20 mg. of the sensitising dye as prepared above and having a sensitisation maximum at 510 nm.

5 EXAMPLE 3 3-[2-(1,3-diethyl-5,6dichloro 2 benzimidazolinylidene)-ethylidene]-4-oxo 3,4 dihydro-lH-l,4-thiazino [4,3-a]benzimidazole H2 (62115 S i I O1 (hon-011: N--

| o1 -IEI f CgHs To a suspension of 2.04 g. of 4-oxo-3,4-dihydro-1H- 1,4-thiazino[4,3-a]benzimidazole and 5.37 g. of 1,3-diethyI-Z-[B-(p toluenesulfonanilido)-vinyl]-5,6-dichlorobenzimidazolium chloride and 40 ccs. of pyridine, 1.4 cc. of triethylamine is added. The mixture is boiled for 10 min., whereupon it is poured into water. The formed dye precipitate is filtered with suction and purified by recrystallisation from a mixture consistnig of equal parts of pyridine and isopropanol. Yield: 0.9 g. Melting point: above 260 C. k =493 nrn. e=8.70 10 1 kg. of a gelatino-silver chloride emulsion is sensitised with 30 mg. of the sensitising dye as described above and having a sensitisation maximum at 520' nm.

EXAMPLE 4 3-[2-(1,3-diethyl cyano-2-benzimidazolinylidene)- ethylidene]-4-oxo-3,4-dihydro 1H 1,4 thiaZino[4,3-a]

This product is prepared in the same way as that of Example 3 but after having replaced 5.37 g. of 1,3-diethyl-Z-[B-(p-toluenesulfonanilido)-vinyl]5,6 dichlorobenzimidazolium chloride by 4.95 g. of 1,3-diethyl-2-[fi- (p-toluenesulfonanilido)-vinyl] 5 cyanobenzimidazolium chloride. Melting point: 256 C. :492 nm. e=9.55 x

1 kg. of a gelatino-silver chloride emulsion is sensitised with 30 mg. of the sensitising dye as described above and having a sensitisation maximum at 525 nm.

EXAMPLE 5 3-[2-(l-ethyl 2 pyrrolidinylidene)-ethylidene]-4- 3,4 dihydro-lH-l,4-thiazino 4,3-a]benzimidazole To a solution of 3.28 g. of 1-methyl-2-(ii-anilinovinyl)- pyrrolinium iodide and 2.04 g. of 4-oxo-3,4-dihydro-1H- 1,4-thiazino[4,3-a]benzimidazole in ccs. of acetic anhydride, 1.4 cc. of triethylamine is added. The mixture is boiled for min. After the addition of water, the resulting precipitate is collected by filtration and purified by recrystallisation from ethanol. Yield: 0.15 g. Melting point: above 275 C. :443 nm. e=5.01 10 1 kg. of a gelatino-silver chloride emulsion is sensitized with 15 mg. of the sensitising dye as described above and having a sensitisation maximum at 480 nm.

As appears from the examples, the new merocyanine dyes are useful for extending the spectral sensitivity of photographic silver halide emulsions, especially of the customarily employed gelatino-silver chloride, gelatinosilver chloride-bromide, gelatino-silver bromide, gelatinosilver bromo-iodide and gelatino-silver chloro-bromoiodide emulsions. Photographic emulsions containing Water-permeable coloids other than gelatin, such as agaragar, zein, collodion, water-soluble cellulose derivatives, poly(vinyl alcohol) or other hydrophilic synthetic or natural resins or polymeric compounds, can, however, also be sensitised with the merocyanine dyes according to the present invention.

In order to prepare photographic emulsions sensitised according to this invention by one or more of the new merocyanine dyes, the latter are incorporated in the photographic emulsion by one of the methods customarily em ployed in the art. In practice, it is convenient to add the dyes to the emulsion in the form of a solution in an appropriate solvent. The new merocyanine dyes can be added at any stage of the preparation of the emulsion and should be uniformly distributed throughout the emulsion. The concentration of the dyes in the emulsion may vary widely, for example from 1 to 200 mg. per kg. of flowable emulsion and will vary according to the effect desired. The most suitable and most economical concentration for any particular emulsion will be apparent to those skilled in the art, upon making the ordinary tests and observations customarily used in the art of emulsion making.

The new merocyanine dyes can be incorporated into photographic emulsions the general sensitivity of which has been increased by physical and chemical ripening. As suitable chemical sensitisers may be mentioned the wellknown sulphur sensitisers such as allyl isothiocyanate, allyl thiourea, sodium thiosulphate, potassium selenocyanide, the natural sensitisers originating in the gelatin, the reducing sensitisers such as imino-aminomethanesulphinic acid and the derivatives thereof, further cadmium salts, and the salts of noble metals such as gold, platinum and palladium.

In preparing the photographic emulsions according to the invention, the usual and suitable addenda such as antifogging agents, stabilisers, antibronzing agents, hardeners, wetting agents, plasticisers, development accelerators, colour couplers, fluorescent brighteners and ultra-violet screening compounds can moreover be incorporated in the emulsion in the manner customarily employed in the art. In this respect it may be mentioned that the sensitivity of the silver halide emulsions sensitised. according to the process of the present invention is not adversely affected but rather enhanced by the presence therein of certain fluorescent compounds.

The photographic emulsions optically sensitised according to the invention may further be supersensitised and/or hypersensitised by one of the methods known to those skilled in the art.

Emulsions sensitised with the new merocyanine dyes can be coated in the usual manner on a suitable support such as glass, cellulose derivative filrn, resin film or paper.

Although the merocyanine dyes according to the present invention are especially useful for extending the spectral sensitivity of silver halide emulsions, the merocyanine dyes according to this invention also possess optically sensitising properties for photoconductive compounds e.g. photoconductive zinc oxide.

The new merocyanine dyes according to this invention can be incorporated in the photoconductive layer by one of the methods customarily employed in the art.

The merocyanine dyes according to this invention are incorporated preferably in a photoconductive layer such as a photoconductive layer containing photoconductive zinc oxide, in an amount of 0.05 to 0.1 mole percent in respect of the photoconductive substance.

The following sensitisation values are obtained from a photoconductive zinc oxide layer containing per mole of photoconductive zinc oxide 0.1 mole of dyestuff as indicated in the following table.

Total Optical sensitivity sensitisation (relative maximum values) (nm.)

Dyestufi according to .i 100 Example 1 530 450 Example 2 260 460 Example 3 800 500 Example 4 700 500 Example 5 260 455 What we claim is:

1. A light-sensitive element containing light-sensitive silver halide optically sensitized with a merocyanine dye containing a benzimidazothiazinone nucleus.

2. A light-sensitive element containing lightsensitive silver halide optically sensitized with a merocyanne dye containing at least one heterocyclic residue according to the following structure:

wherein each of R and R represents hydrogen or halogen. 3. The light-sensitive element of claim 1 wherein the merocyanine dye has the formula:

wherein R and R each represents hydrogen or halogen,

R represents an alkyl radical,

Z represents the atoms necessary to complete a heterocyclic nucleus containing to 6 atoms in the heterocyclic ring, and

n represents 1 or 2.

4. A light-sensitive element containing photoconductive zinc oxide optically sensitized with a merocyanine dye containing a benzimidazothiazinone nucleus.

5. A light-sensitive element containing photoconductive zinc oxide optically sensitized with a merocyanine dye containing at least one heterocyclic residue according to the following structure:

8 wherein each of R and R represents hydrogen or halogen. 6. The light-sensitive element of claim 4 wherein the merocyanine dye has the formula:

7. A photographic light-sensitive silver halide emulsion containing a merocyanine dye containing a benzimidazothiazinone nucleus.

8. A photographic light-sensitive silver halide emulsion containing a merocyanine dye containing at least one heterocyclic residue according to the following formula:

each of R and R represents hydrogen or halogen. 9. The emulsion of claim 7 wherein the merocyanine dye has the formula:

R and R each represents hydrogen or halogen,

R represents an alkyl radical,

Z represents the atoms necessary to complete a heterocyclic nucleus containing 5 to 6 atoms in the heterocyclic ring, and

n represents 1 or 2.

References Cited UNITED STATES PATENTS 2,526,632 10/1950 Brooker et a1. 96-102 2,548,571 4/1951 Lare et a1 96l02 3,326,688 6/1967 Jenkins 96-406 GEORGE F. LESMES, Primary Examiner J. P. BRAMMER, Assistant Examiner U.S. Cl. X.R. 

